Annotation Tool - How to control placement of drawing
By default the depth is determined by the 3D cursor position.
All the settings are in the N panel &gt; Tool &gt; Active Tool &gt; Placement, you can choose between:

3D Cursor: The annotation is drawn perpendicularly to your view and it is placed where your 3D cursor is.
View: The annotation does not depend on the 3D view.
Surface, The annotation is drawn on the surface of the objects.


Also good to know: Ctrl left click to erase (if you use the D shortcut to draw annotation, the erase shortcut is D and right click).
Click on N panel &gt; Tool &gt; Active Tool &gt; Note to set the thickness and color of the stroke.
CLick on the &quot;+&quot; and &quot;-&quot; button to create or delete an annotation, click on the eye icon to switch it visibility:

If you move in the Timeline and draw again, by default it will create a new annotation that starts at this frame. If you want to keep the previous one, click on the Note &gt; Frame: X (Locked) button. To unlock, click again on this button. To delete this annotation on all its frames, click on the X button.